76 



BULLETIN 536, U. S. DEPARTMENT OF AGRICULTURE. 



weather. As the females are capable of living long periods and of 

 depositing small batches of eggs almost daily, the generations become 

 hopelessly confused. In those portions of the islands where the 

 winter monthly means drop to about 68° F., as in the Kona district 

 of Hawaii at about 1,30.0 feet elevation, there may be not more than 

 10 to 12 generations. The number of generations is naturally less in 

 colder habitats. At Strawberry, a ranch station on Hawaii at about 

 4,500 feet elevation, there appears to be only a single generation a year, 

 which is evident in the last fruit to ripen on a few peach trees. 



As may be expected, adults are abundant at all seasons in the 

 littoral regions of Hawaii where host plants are grown. With the 

 hopeless confusion of generations that exists, there can be no seasonal 

 broods. Instead, adults may be found actively ovipositing every 

 day of the year. That the cooler weather of the winter months does 

 lengthen the life cycle has already been proved. This slowing down 

 of development naturally results in the emergence of fewer adults. 

 This is indicated bv the data of Table XXI. 



Table XXI. — Seasonal abundance of adult Ceratitis capitata at Honolulu. 



[Average daily catch of 147 kerosene traps for the weeks indicated below, from Apr. 21, 1913, to Aug. 4, 1914. 



Traps exposed in Punahou district of Honolulu, east of Punahou Street and south of Wilder Avenue.] 



Date. 



Num- 

 ber. 



Date. 



Num- 

 ber. 



Date. 



Num- 

 ber. 



Date. 



Num- 

 ber. 



Date. 



Num- 

 ber. 



Apr. 26.. 

 May 3... 



279 



Aug. 2 



905 



Nov. 8 



353 



Feb. 13.... 



58 



May 23. . . . 



291 



347 



Aug. 9 



937 



Nov. 15... 



237 



Feb. 20.... 



117 



May 30. . . . 



259 



May 10.. 



677 



Aug. 16... 



763 



Nov. 22... 



137 



Feb. 28.... 



64 



June 6 



389 



May 17.. 



901 



Aug. 23-. - 



562 



Nov. 29... 



132 



Mar. 7 



71 



June 13 



729 



May 24. . 



1,738 



Aug. 30... 



439 



Dec. 6 



219 



Mar. 14.... 



49 



June 20.... 



1,074 



May 31.. 



1,498 



Sept. 6.... 



316 



Dec. 13.... 



324 



Mar. 21.... 



74 



June 27 



935 



June 7... 



1,413 



Sept. 13... 



219 



Dec. 19.... 



355 



Mar. 28.... 



64 



July 4 



1,676 



June 14.. 



1,047 



Sept. 20... 



152 



Dec. 27.... 



240 



Apr. 4 



92 



July 11.... 



2,503 



June 21 . . 



855 



Sept. 27... 



141 



Jan. 2 



176 



Apr. 11.... 



123 



July 18. . . . 



2,002 



June 28.. 



1,084 



Oct. 4 



167 



Jan. 9 



48 



Apr. 18.... 



150 



July 25. . . . 



1,677 



July 5... 



769 



Oct. 11... 



200 



Jan. 16 



84 



Apr. 25 



124 



Aug. 1 



964 



July 12. . 



723 



Oct. 18.... 



200 



Jan. 24.... 



46 



May 2 



188 



Aug. 4 



523 



July 19.. 



769 



Oct. 25.... 



205 



Jan. 31 



51 



Mav 9 



343 







July 26.. 



727 



Nov. 1 



270 



Feb. 7 



72 



May 16 



455 







These data on the number of males captured in 147 traps in an area 

 equal to about four city blocks are taken as indicating the relative 

 abundance of adults in a single year, in a section of Honolulu where 

 many host trees occur. The adults are most numerous during late 

 May, June, and July, and less numerous during January, February, 

 and March. The numerical abundance of adults in Honolulu, where 

 the climate never seriously retards development, is affected more by 

 the numerical abundance of ripening host fruits, which is greatest 

 during the early summer and least during the winter. The fact that 

 there are relatively fewer adults during the winter months is of no 

 practical value to growers of fruit in Hawaii, since the smaller amount 

 of fruit ripening at that season is nearly as badly affected as are the 

 fruits ripening during the summer. 



